高静压技术对豆浆中脂肪氧合酶的钝化效果及其动力学分析

Effects of High Hydrostatic Pressure(HHP) on the Inactivation of Lipoxygenase(LOX) in Soymilk

研究了高静压技术(HHP)对豆浆中脂肪氧合酶(LOX)活性的钝化作用,并进行失活动力学分析。结果表明:HHP处理能显著钝化豆浆中LOX活性。用300～600MPa压力处理5～20min,对LOX活性有显著的钝化效果(P<0.05),并且随处理压力和处理时间的增加,酶的失活率提高。当压力500MPa,保压时间0min时也有一定的钝化LOX效果;当压力600MPa处理10min以上,豆浆LOX活性被完全抑制。用500MPa处理5min,可以达到与传统巴氏杀菌相同的钝酶效果(P>0.05)。HHP技术钝化豆浆LOX的过程可用一级动力学模型拟合(R2>0.900)。随着压力的升高和处理时间的延长,k值逐渐升高,D值逐渐减小;动力学参数ZP和Va分别为125.94MPa和-45.290cm3/mol。HHP技术在钝化豆浆中脂肪氧合酶活性方面比传统巴氏杀菌彻底,效果更好。其在改善豆浆品质方面具有良好的应用前景。

Effects of high hydrostatic pressure（HHP） on the inactivation of lipoxygenase（LOX） in soymilk was investigated.The LOX activity in soymilk was significantly inactivated by HHP,and the LOX activity gradually decreased with the increases of treatment pressure and/or holding time（P0.05）.The LOX activity in the soymilk was also inactivated under 500 MPa with no holding time,and the LOX activity was completely inhibited under 600 MPa with holding time more than 10 min.Compared with the pasteurization treatment（62～65℃,30 min）,the LOX activity had no significantly difference when the soymilk was treated under 500 MPa for 5 min（P0.05）.The inactivation kinetics of LOX under HHP could be adequately described by the first-order model,and the Eyring equation was fitted with the experimental data.The rate constants k increased and the decimal reduction time D reduced with the increase of pressure.The values of kinetic parameters,ZP and Va,were deduced as 125.94 MPa and-45.290 cm3/mol,respectively.The effect of HHP on the inactivation of LOX in soymilk was more effective than that treated by the traditional pasteurization.Therefore,the HHP is a promising technology in the application for soymilk industry.